Wheel chock system

ABSTRACT

A wheel restraint for restraining a vehicle at a loading dock includes various features such as, a wheel chock supported by a spring loaded articulated arm with a spring that can be selectively tightened or released, a sensor that detects whether the chock is solidly against a base plate or floor, a bi-directional pivotal joint between the articulated arm and the wheel chock to ensure that the chock can sit squarely on a mating base plate, a wheel chock that meshes with a hydraulically actuated base plate, pivotal or otherwise movable backstops that prevent a wheel chock from sliding out of position, and a base plate cleaning system. The cleaning system might include a vehicle-actuated brush, fluid spray nozzles, electric heater and removable cover plates.

FIELD OF THE DISCLOSURE

The present disclosure generally pertains to restraining a vehicle at aloading dock and more specifically to a wheel chock system.

BACKGROUND OF RELATED ART

When a truck, trailer or some other vehicle is parked at a loading dock,often some sort of vehicle restraint is used to keep the truck frominadvertently moving away from an elevated platform of the dock. Thisallows a forklift truck to safely drive between the dock platform andthe truck for the purpose of loading or unloading the cargo inside thetruck.

There are a variety of vehicle restraints available that can beinstalled at a loading dock for engaging the truck's RIG (Rear ImpactGuard), also known as an ICC bar. An ICC bar is a beam that extendshorizontally across the rear of a truck, just below the truck bed. Itsprimary purpose is to prevent an automobile from under-riding the truckin a rear-end collision. However, not all trucks have an ICC bar thatcan be readily engaged by an ICC-style restraint. Moreover, ICC bars arenot prevalent outside the United States, so in those cases a wheelrestraint can be used for blocking one or more of the truck's wheels.

Perhaps the most common wheel restraint is simply a wheel chock thatwedges between the driveway and the underside of the wheel. However,wheel chocks often slip out of position on driveways that are slipperydue to oil, rain, ice, sand, gravel or dirt. Moreover, wheel chocksusually are loose items that do not permanently attach to the loadingdock area, so they often get misplaced.

One solution to these problems is disclosed in U.S. Pat. No. 7,032,720,which shows a wheel chock that is coupled to the loading dock by way ofan articulated arm. To help prevent the chock from slipping out of itswheel-blocking position, the chock can be placed in mating engagementupon a serrated base plate that is anchored to the driveway. Althoughsuch a system can be effective, it does have some drawbacks.

First, a counterweight spring on the arm tends to prevent the wheelchock from resting its full weight upon the base plate. Second, thelength to which the arm must extend to reach the wheel can adverselyaffect the angular relationship (about a vertical axis) between themating surfaces of the chock and base plate. Third, although the '720device includes a sensor for detecting the presence of a wheel, thesensor does not indicate whether the chock is fully engaged with theserrations of the base plate. And fourth, dirt, ice and othercontaminants could hinder the engagement between the chock and the baseplate, thus reducing the effectiveness of the chock.

Consequently, a need exists for a wheel chock system that overcomes thelimitations and drawbacks of current systems.

SUMMARY

In some embodiments, a wheel chock for restraining a vehicle at aloading dock is supported by a spring loaded articulated arm, whereinthe spring force can be released.

In some embodiments, a wheel chock is supported by an articulated armthat includes a pivotal joint where the arm connects to the chock,wherein the joint permits the chock to rotate relative to the arm abouta vertical axis.

In some embodiments, a wheel chock includes a sensor that detectswhether the chock is fully engaged with a lower support surface.

In some embodiments, a manually manipulated wheel chock is coupled to ahydraulic cylinder that can forcibly draw the chock against a vehicle'swheel.

In some embodiments, a wheel chock can be manually placed upon a matingbase plate, and a hydraulic cylinder can move the plate to force thechock against a vehicle's wheel.

In some embodiments, a set of hooks or latches selectively engage andrelease a wheel chock from a lower support surface that is anchored tothe ground. In some embodiments, a manually operated wheel chockincludes a cleaning system that inhibits debris, ice and othercontaminants from accumulating on a surface upon which the chock isplaced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view a wheel restraint in a holding position.

FIG. 2 is a perspective view of the wheel restraint of FIG. 1 butshowing the restraint in a release position.

FIG. 3 is a perspective view of a wheel chock being lowered upon amating base.

FIG. 4 is an end view looking toward the dock face and showing a wheelchock being lowered upon a base.

FIG. 5 is a perspective view similar to FIG. 1 but showing anotherembodiment.

FIG. 6 is a side view of a wheel chock in a release position.

FIG. 7 is a side view similar to FIG. 6 but showing the chock in aholding position.

FIG. 8 is an end view similar to FIG. 4 but showing another embodiment.

FIG. 9 is a side view similar to FIG. 7 but showing the wheel chock ofFIG. 8.

FIG. 10 is a top view of a cleaning system for the base of a wheelrestraint system.

FIG. 11 is a top view similar to FIG. 10 but showing a brush sweepingacross the base.

FIG. 12 is a top view similar to FIGS. 10 and 11 but showing the wheelrestraint system in a holding position.

FIG. 13 is a top view similar to FIG. 10 but showing an alternateembodiment of a cleaning system.

FIG. 14 is a top view similar to FIG. 13 but showing yet anotherembodiment.

FIG. 15 is a top view similar to FIG. 14 but showing the wheel restraintsystem in a holding position.

DETAILED DESCRIPTION

FIGS. 1 and 2 show a wheel restraint system 10 for restraining at leastone wheel 12 of a vehicle 14 at a loading dock 16. Restraint 10 is shownin a holding position in FIG. 1 and is shown in a release position inFIG. 2. In the holding position, restraint 10 helps hold vehicle 14adjacent to a dock face 18 so that cargo can be safely conveyed on andoff of vehicle 14. In some cases, a conventional dock leveler 20 can beused to facilitate the loading and unloading operations. An uppersection of vehicle 14 is shown in phantom lines to more clearly show thesubject invention.

Wheel restraint 10 includes a wheel chock 22 that may, for example, restupon a base 24 (lower support surface) when restraint 10 is in theholding position of FIG. 1. To limit the wheel chock's horizontalmovement (particularly in a forward direction away from dock face 18)base 24 and/or chock 22 may include an interlocking feature such as atooth 26 or 28 that engages a mating feature in the opposing surface, asshown in FIGS. 3 and 4. The various shapes, sizes, quantities andpositions of tooth 26 and 28 are too numerous to mention, and it will beappreciated by those of ordinary skill in the art that the number ofpossible designs is unlimited.

To assist the repositioning of chock 22 between the holding and releasepositions, an elevated articulated arm 30 couples chock 22 to an anchor32 that is attached to dock 16. Various joints of arm 30, anchor 32and/or chock 22 enable chock 22 to be moved in three-dimensional space.To ensure that chock 22 can rest flat upon base 24, a joint 34 couplingarm 30 to chock 22, as shown in FIG. 4, permits chock 22 to rotate abouta substantially horizontal axis 36 that is substantially parallel todock face 18. To ensure the horizontal footprint of chock 22 can liesquare to base 24 regardless of the chock's distance from dock face 18,joint 34 also allows chock 22 to rotate about a second axis 38 that isperpendicular to or at least traverses an imaginary horizontal plane 40.Joint 34 could be any multi-axis joint including, but not limited to, auniversal ball joint.

To further assist the manual repositioning of chock 22, a spring 42coupled to arm 30 helps offset the weight of chock 22 and arm 30.Counteracting the weight of arm 30 and chock 22 can be helpful whilepositioning chock 22; however, counteracting that weight is not alwaysdesired. The weight of arm 30 and chock 22, for instance, can actuallybe useful in holding chock 22 solidly against base 24. Thus, a springrelease device 44 might be added so that spring 42 can be selectivelystressed (FIG. 2) and released (FIG. 1). In the relaxed position of FIG.1, the stress in spring 42 is reduced but does not necessarily have tobe reduced to zero. In some examples, device 44 is a lever that can betoggled over center by rotating the lever about a pivot point 46. Tolimit the rotation of the lever, an end stop 48 on device 44 engages arm30.

When chock 22 is in the holding position of FIG. 1, a sensor 50 mountedto chock 22 can be used determine whether chock 22 is actually fullyengaged with base 24. Sensor 50 can be any device that can provide asignal 52 in response to proper engagement between chock 22 and base 24.Examples of sensor 50 include, but are not limited to, a proximityswitch (e.g., Hall effect sensor), electromechanical switch,photoelectric eye, etc. Signal 52 can be transmitted via wires througharm 30 or can be transmitted wirelessly to control one or more signallights 54.

FIG. 5 shows another example wherein a hydraulic cylinder 56 (hydraulicarm) replaces articulated arm 30. By controlling or stopping the flow ofhydraulic fluid using conventional techniques, cylinder 56 can help holdwheel chock 22 at its holding position, as shown in FIG. 5. An anchor 58with a pivotal joint 60 allows repositioning of cylinder 56 and chock22. Similar to spring 42 of wheel restraint 10, a spring 62 can be usedto help offset the weight of cylinder 56 and chock 22.

FIGS. 6 and 7 show a wheel chock 64 and a sliding base 66 with analternate tooth design. This wheel restraint system includes a linearactuator 68 (e.g., a hydraulic cylinder, lead screw, etc.) that is heldin place by an anchor 70 fixed to the loading dock. Actuator 68 can drawchock 64 tightly up against wheel 12 by pulling base 66 towards dockface 18, as indicated by arrow 72. To release wheel 12, actuator 68extends to push base 66 and chock 64 away from dock face 18. Once chock64 is no longer tightly up against wheel 12, chock 64 can be manuallylifted from base 66. The mechanism for maintaining the chock in positionshown in FIGS. 6 and 7 could be used with a manual chock, or oneconnected to a mechanism for facilitating chock placement such as thatshown in FIGS. 1 and 2. The same holds true for the remaining examplesor concepts described herein.

FIGS. 8 and 9 show a wheel chock 72 resting upon a stationary base 74.To limit the chock's movement away from dock face 18, one or more hooksor latches 76 are pivotally connected to chock 72 or base 74. For theillustrated example, a hinge 78 connects each latch 76 to base 74 suchthat selected latches 76 can be pivoted upward to limit the movement ofchock 72. Although it is generally more important to limit the chock'smovement away from dock face 18, latches 76 and their mountingconfiguration to base 74 or chock 72 could be such that latches 76restrict the chock's movement in other directions as well.

FIGS. 10, 11 and 12 show a wheel chock system 80 that includes acleaning system 82 for inhibiting contaminants, such as dirt and ice,from accumulating on a base 84. To prevent ice from accumulating, aheating element 86, such as electrical resistive wire or some otherheat-generating source, is installed in proximity (i.e., in heatexchange relationship) with base 84.

A brush 88 mounted to a movable arm 90 can be used to sweep dirt frombase 84. One end 92 of arm 90 is pivotally coupled to an anchor 94. Anopposite end 96 of arm 90 provides a cam surface 98 against which wheel12 can push so that as a vehicle backs into the loading dock, theengagement of wheel 12 against cam surface 98 forces brush 88 to sweepacross base 84. When the vehicle departs, a spring 100 can be used topull arm 90 back to its position of FIG. 10. Alternatively, arm 90 couldbe power actuated. A linearly movable brush is also well within thescope of the invention.

FIG. 13 shows an alternative cleaning system 102 that includes one ormore nozzles 104 that discharges a fluid 106 (e.g., air, water or anice-thawing liquid) to clear contaminants from a base 108 or some otherlower support surface. Fluid discharge can be triggered manually, or itcan be triggered automatically in response to a timer or a sensorresponsive to a vehicle or the presence of a contaminant.

FIGS. 14 and 15 show a cleaning system 110 wherein one or more covers112 help shelter unused portions of base 108. For the illustratedexample, covers 112 are moved manually by simply lifting the covers onor off of base 108. Alternatively, covers 112 can be hinged to base 108so that covers 112 can be pivoted on and off.

Although the invention is described with respect to various examples,modifications thereto will be apparent to those of ordinary skill in theart. Many of the wheel restraint features disclosed herein areinterchangeable among the various examples. The scope of the invention,therefore, is to be determined by reference to the following claims:

1. A wheel restraint system that can engage a wheel of a vehicle at aloading dock, the wheel restraint system comprising: an anchor mountableto the loading dock; a wheel chock selectively movable to a holdingposition and a release position such that in the holding position, thewheel chock obstructs the wheel; and in the release position, the wheelchock is clear of the wheel; an arm that couples the wheel chock to theanchor; and a spring coupled to the arm and being selectively movable toa stressed position and a relaxed position such that the arm supportsmore of the wheel chock's weight when the spring is in the stressedposition than when the spring is in the relaxed position.
 2. The wheelrestraint system of claim 1, wherein the arm extends to an elevationthat is higher than the wheel chock.
 3. The wheel restraint system ofclaim 1, wherein the arm is articulated.
 4. The wheel restraint systemof claim 1, further comprising a base that is underneath and engagingthe wheel chock when the wheel chock is in the holding position but isseparated from the wheel chock when the wheel chock is in the releaseposition.
 5. A wheel restraint system that can engage a wheel of avehicle at a loading dock that includes a dock face, the wheel restraintsystem comprising: an anchor mountable to the loading dock; a wheelchock selectively movable to a holding position and a release positionsuch that in the holding position, the wheel chock obstructs the wheel;and in the release position, the wheel chock is clear of the wheel; anarm coupled to the anchor; and a joint coupling the arm to the wheelchock such that the joint permits: a) relative rotation between thewheel chock and the arm about a substantially horizontal axis that issubstantially parallel to the dock face, and b) relative rotationbetween the wheel chock and the arm about a second axis that traversesan imaginary horizontal plane.
 6. The wheel restraint system of claim 5,wherein the second axis is substantially vertical.
 7. The wheelrestraint system of claim 5, wherein the arm extends to an elevationthat is higher than the wheel chock.
 8. The wheel restraint system ofclaim 5, wherein the arm is articulated.
 9. The wheel restraint systemof claim 5, further comprising a base that is underneath and engagingthe wheel chock when the wheel chock is in the holding position but isseparated from the wheel chock when the wheel chock is in the releaseposition.
 10. A wheel restraint system that can be placed upon a lowersupport surface to engage a wheel of a vehicle at a loading dock, thewheel restraint system comprising: a wheel chock selectively movable toa holding position and a release position such that in the holdingposition, the wheel chock rests upon and engages the lower supportsurface so as to obstruct the wheel; and in the release position, thewheel chock is clear of the wheel; and a sensor carried by the wheelchock and being responsive to the position of the wheel chock relativeto the lower support surface, the sensor provides a signal thatindicates whether the wheel chock is resting upon and engaging the lowersupport surface.
 11. The wheel restraint system of claim 10, wherein thelower support surface includes a base that meshes with the wheel chock.12. The wheel restraint system of claim 11, further comprising a toothprotruding from at least one of the wheel chock and the base, whereinthe tooth helps maintain engagement between the wheel chock and thebase.
 13. The wheel restraint system of claim 10, further comprising: ananchor mountable to the loading dock; and an arm that couples the wheelchock to the anchor.
 14. A wheel restraint system that can engage awheel of a vehicle at a loading dock, the wheel restraint systemcomprising: an anchor mountable to the loading dock; a wheel chockselectively movable to a holding position and a release position suchthat in the holding position, the wheel chock obstructs the wheel; andin the release position, the wheel chock is clear of the wheel; and ahydraulic arm that couples the wheel chock to the anchor such that whenthe wheel chock is in the holding position, the hydraulic arm can urgethe wheel chock against the wheel, the hydraulic arm is manually pivotalfor moving the wheel chock between the holding position and the releaseposition.
 15. The wheel restraint system of claim 14, further comprisinga base that is underneath and engaging the wheel chock when the wheelchock is in the holding position but is separated from the wheel chockwhen the wheel chock is in the release position.
 16. The wheel restraintsystem of claim 15, further comprising a tooth protruding from at leastone of the wheel chock and the base, wherein the tooth helps maintainengagement between the wheel chock and the base.
 17. A wheel restraintsystem that can engage a wheel of a vehicle at a loading dock, the wheelrestraint system comprising: an anchor mountable to the loading dock; abase; a wheel chock selectively movable to a holding position and arelease position such that in the holding position, the wheel chockengages the base and obstructs the wheel; and in the release position,the wheel chock is clear of the wheel and spaced apart from the base; atooth protruding from at least one of the wheel chock and the base,wherein the tooth helps maintain engagement between the wheel chock andthe base when the wheel chock is in the holding position; and anactuator coupling the base to the anchor such that when the wheel chockis in the holding position, the actuator can move the base to urge thewheel chock toward the wheel.
 18. The wheel restraint system of claim17, wherein the actuator is a hydraulic cylinder.
 19. A wheel restraintsystem that can engage a wheel of a vehicle at a loading dock, the wheelrestraint system comprising: a base; a wheel chock selectively movableto a holding position and a release position such that in the holdingposition, the wheel chock engages the base and obstructs the wheel; andin the release position, the wheel chock is clear of the wheel andspaced apart from the base; and a pivotal latch extending from at leastone of the wheel chock and the base, wherein the pivotal latch helpsmaintain engagement between the wheel chock and the base when the wheelchock is in the holding position.
 20. The wheel restraint system ofclaim 19, further comprising: an anchor mountable to the loading dock;and an arm that couples the wheel chock to the anchor.
 21. The wheelrestraint system of claim 20, wherein the arm is articulated.
 22. Awheel restraint system that can be placed upon a lower support surfaceto engage a wheel of a vehicle at a loading dock, wherein the lowersupport surface is subject to a contaminant, the wheel restraint systemcomprising: a wheel chock selectively movable to a holding position anda release position such that in the holding position, the wheel chockrests upon and engages the lower support surface so as to obstruct thewheel; and in the release position, the wheel chock is clear of thewheel; and a cleaning system in proximity with the lower support surfaceto inhibit the contaminant from accumulating on the lower supportsurface.
 23. The wheel restraint system of claim 22, wherein thecleaning system includes a nozzle that aims a fluid at the lower supportsurface.
 24. The wheel restraint system of claim 23, wherein the fluidis air.
 25. The wheel restraint system of claim 23, wherein the fluid isa liquid.
 26. The wheel restraint system of claim 22, wherein thecleaning system includes an electric heater in heat transferrelationship with the lower support surface.
 27. The wheel restraintsystem of claim 22, wherein the cleaning system includes a brush thatmoves across the lower support surface.
 28. The wheel restraint systemof claim 22, wherein the cleaning system includes a scraper that movesacross the lower support surface.
 29. The wheel restraint system ofclaim 22, wherein the cleaning system is actuated by movement of thevehicle.
 30. The wheel restraint system of claim 22, wherein thecleaning system includes a cover that selectively covers and exposes thelower support surface.